CN108700497B

CN108700497B - Fluid sampling

Info

Publication number: CN108700497B
Application number: CN201680070457.7A
Authority: CN
Inventors: J·霍尔; S·拉泰瑞
Original assignee: SGS North America Inc
Current assignee: SGS North America Inc
Priority date: 2015-10-27
Filing date: 2016-10-27
Publication date: 2022-01-11
Anticipated expiration: 2036-10-27
Also published as: US20170115190A1; SG11201803486TA; PT3368878T; KR20180108569A; US9846109B2; ES2934142T3; CN108700497A; WO2017075152A1; EP3368878A1; EP3368878B1

Abstract

A fluid sampling device, comprising: a first conduit configured to couple an outlet of a fluid source to a sample inlet; a second conduit configured to couple the sample outlet to an inlet of a fluid source; an expansion chamber comprising an inlet and an outlet coupled to the first and second conduits through a valve assembly; and a pressure relief valve configured to couple an outlet of the expansion chamber to an inlet of the fluid source. The fluid sampling device facilitates the collection of a fluid sample and subsequent purging of its internal components while inhibiting the release of sample fluid to the surrounding environment, thereby protecting the environment and sampling personnel from harmful chemical release. The fluid sampling device may facilitate a sample collection process that provides a closed loop flushing and expansion operation for obtaining a representative sample of a sample container of a suitable fill density.

Description

Fluid sampling

Priority requirement

This application claims priority from U.S. patent application No.14/923,997 filed on 27/10/2015, the entire contents of which are incorporated herein by reference.

Technical Field

The present description generally relates to systems, devices, and methods for collecting fluid samples.

Background

Fluid sampling devices are used in many industries to collect measured volumes of fluid from separate fluid sources for transport to remote testing locations. Testing of the fluid sample may include: detecting the presence of contaminants and/or determining the physical properties and composition of the fluid. Typically, fluid from a fluid source is circulated through a fluid sampling device, which facilitates the capture of a representative sample in a sample container that is detachable from the sampling device.

Disclosure of Invention

This specification describes technologies relating to systems, devices, and methods for collecting fluid samples.

In one aspect of the present disclosure, a fluid sampling device includes: a first conduit configured to couple an outlet of a fluid source to a sample inlet; a second conduit configured to couple the sample outlet to an inlet of a fluid source; an expansion chamber comprising an inlet and an outlet coupled to the first and second conduits through a valve assembly; and a pressure relief valve configured to couple an outlet of the expansion chamber to an inlet of the fluid source. The first conduit is further configured to be coupled to a source of inert gas such that: the inert gas from the inert gas source pushes fluid within the first and second conduits toward the inlet of the fluid source when the valve assembly is in the first position, thereby purging the first and second conduits, and the inert gas from the inert gas source pushes fluid within the expansion chamber toward the inlet of the fluid source when the valve assembly is in the second position and the pressure relief valve is open, thereby purging the expansion chamber.

In some embodiments, the fluid comprises a liquefied gas.

In some embodiments, the inert gas comprises at least one of: carbon dioxide, molecular oxygen and molecular nitrogen.

In some embodiments, the fluid sampling device further comprises a portable housing supporting the first and second conduits, the expansion chamber, and the pressure relief valve.

In some embodiments, the sample inlet and outlet comprise quick connect fittings.

In some embodiments, the valve assembly comprises a series valve comprising a pair of three-way valves, a first of the three-way valves coupling the inlet of the expansion chamber to the second conduit and a second of the three-way valves coupling the outlet of the expansion chamber to the first conduit.

In some embodiments, the fluid sampling device further comprises a booster pump configured to be coupled to the first conduit, and operation of the booster pump induces fluid from the outlet of the fluid source to flow through the first conduit to the sample inlet. In some embodiments, the booster pump includes a gas driver, and a gas inlet of the gas driver is configured to be coupled to a source of inert gas. In some embodiments, the fluid sampling device further comprises an inert gas routing valve configured to regulate coupling of the inert gas source between the first conduit and the gas inlet of the gas driver of the booster pump. In some embodiments, the fluid sampling device further comprises a booster pump valve configured to regulate coupling of the first conduit with the high pressure outlet of the booster pump.

In another aspect of the present disclosure, a fluid sampling device includes: a first conduit configured to couple an outlet of a fluid source to a sample inlet; a second conduit configured to couple the sample outlet to an inlet of a fluid source; an expansion chamber comprising an inlet and an outlet coupled to the first and second conduits through a valve assembly; a booster pump configured to be coupled to the first conduit such that operation of the booster pump induces fluid from the outlet of the fluid source to flow through the first conduit to the sample inlet; and a portable housing supporting the first and second conduits, the expansion chamber, and the booster pump.

In some embodiments, the fluid sampling device further comprises a sample container coupled to the sample inlet and the sample outlet. In some embodiments, when the valve assembly is in the first position, fluid from the fluid source flows in a closed loop between the sample container and the fluid source, thereby flushing the sample container, and when the valve assembly is in the second position, fluid flows in a closed loop between the sample container and the expansion chamber, thereby expanding a portion of the fluid in the sample container.

In some embodiments, the booster pump includes a gas driver, and a gas inlet of the gas driver is configured to be coupled to a source of inert gas. In some embodiments, the fluid sampling device further comprises an inert gas routing valve configured to regulate coupling of the inert gas source between the first conduit and the gas inlet of the gas driver of the booster pump.

In some embodiments, the fluid sampling device further comprises a booster pump valve configured to regulate coupling of the first conduit with the high pressure outlet of the booster pump.

In yet another aspect of the present disclosure, a method of purging a fluid sampling device includes: coupling a fluid conduit of a fluid sampling device to an inert gas source; circulating an inert gas through the fluid conduit; circulating an inert gas through an expansion chamber of a fluid sampling device; and depositing at least a portion of the inert gas and at least a portion of any sample fluid purged from the fluid conduit and the expansion chamber directly from the fluid sampling device to a sample fluid source coupled to the fluid sampling device.

In some embodiments, the method further comprises circulating the inert gas through a valve assembly comprising a series valve comprising a pair of three-way valves, a first of the three-way valves coupling an inlet of the expansion chamber to the fluid conduit and a second of the three-way valves coupling an outlet of the expansion chamber to the fluid conduit. In some embodiments, the method further comprises adjusting the valve assembly between the first position and the second position to circulate the discrete jet of inert gas through the expansion chamber. In some embodiments, the method further comprises engaging an override device of a pressure relief valve coupled to an outlet of the expansion chamber, thereby fluidly coupling the expansion chamber with the sample fluid source.

The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.

Drawings

FIG. 1 is a schematic view of a fluid sampling device.

Fig. 2 is a perspective view of a portable fluid sampler.

Fig. 3 is a side view of the portable fluid sampling device of fig. 2 carried by a user.

Fig. 4 is a flow chart illustrating a process of operating a fluid sampler.

FIG. 5 is a flow chart illustrating a process for collecting a fluid sample using a fluid sampling device.

FIG. 6 is a flow chart illustrating a process for purging a fluid sampler with an inert gas.

Detailed Description

The present disclosure relates to systems, devices, and methods for collecting a representative fluid sample from a fluid source. In some embodiments, the fluid sampling device is suitably configured to facilitate collection of a fluid sample and subsequent purging of its internal components while inhibiting release of the sample fluid to the surrounding environment. This protects the environment and sampling personnel from harmful chemical release. In some examples, the fluid sampling device may facilitate a sample collection process that provides a closed-loop flushing and expansion operation to obtain a representative sample at a sample container of appropriate fill density. In some examples, the fluid sampling device may facilitate an inert gas purge process that deposits residual sample fluid from a previous sampling operation directly back into the fluid source. In some embodiments, the fluid sampling device includes an internal booster pump operable to maintain the pressure of the sample fluid above its vapor pressure, thereby inhibiting accidental flashing of the two-phase sample fluid to the vapor phase. Thus, the fluid sampling device can facilitate collection of a sample from an external fluid source without a separate pressure source (e.g., a tank or reservoir).

Fig. 1 is a schematic view of an example fluid sampling device 100 in accordance with one or more embodiments of the present disclosure. In this example, fluid sampling device 100 includes a fluid source outlet 102, a fluid source inlet 120, a sample inlet 104, a sample outlet 118, and an expansion chamber 128. As described below, various components of fluid sampling device 100 are fluidly coupled to one another by segments of fluid conduit. The fluid conduit is adapted to deliver pressurized fluid (e.g., liquefied gas) throughout the fluid sampling device 100. Thus, the catheter may be designed or configured differently depending on the application of the sampling device 100. For example, in various applications of the sampling device 100, one or more of the conduit segments may be substantially rigid or flexible conduits formed from a metal or polymeric material. In various applications, the conduit segments are sized to achieve a specified fluid flow characteristic (e.g., flow rate and pressure). In a particular example, one or more of the conduit segments comprises a tubular conduit having a diameter of about 1/4 inches.

In some embodiments, the fluid source outlet 102 and the fluid source inlet 120 comprise couplers (e.g., quick connect couplers) adapted to connect with mating hardware of an external fluid source 10 containing a fluid to be sampled. In some embodiments, the fluid source 10 may comprise a chemical treatment system for treating liquefied petroleum gas. Of course, various other embodiments are contemplated within the scope of the present disclosure. In particular, various other types of fluids for sampling (e.g., other types of liquefied hydrocarbon gases, such as liquefied natural gas and butadiene) and various other types of sampling platforms (e.g., production lines and storage tanks held in fixed facilities or transported on trains, trucks, ships, or barges) are contemplated. In some embodiments, the sample inlet 104 and the sample outlet 118 include couplings (e.g., quick connect couplings) adapted to connect with mating hardware of the sample container 20 suitably designed for retaining the collected fluid sample. In some embodiments, the sample container 20 may comprise a metallic, pressure-rated cylinder equipped with an inlet isolation valve and an outlet isolation valve. Other suitable sample container configurations are also within the scope of the present disclosure.

The fluid source outlet 102 is coupled to the sample inlet 104 by a fluid conduit 106. In this example, fluid conduit 106 includes a first conduit section 108, a second conduit section 112, and a third conduit section 116. Conduit segment 108 leads from fluid source outlet 102 to booster pump valve 110. Conduit section 112 leads from booster pump valve 110 to expansion valve 114 a. Conduit section 116 leads from expansion valve 114a to sample inlet 104. The sample outlet 118 is coupled to a fluid source inlet 120 by a fluid conduit 122. In this example, fluid conduit 122 includes a first conduit section 124 and a second conduit section 126. Conduit segment 124 leads from outlet port 118 to expansion valve 114 b. Conduit section 126 leads from expansion valve 114b to fluid source inlet 120.

The expansion chamber 128 includes a main body 130, an inlet end 132, and an outlet end 134. Inlet end 132 is coupled to expansion valve 114b, and thus fluid conduit 122, by conduit segment 136. The outlet end 134 is coupled to the expansion valve 114a, and thus to the fluid conduit 106, by a conduit segment 138. Thus, during use,

expansion valves

114a and 114b provide a valve assembly 114 to control the flow of fluid between fluid source 10, sample container 20, and expansion chamber 128. In this example, each of the

expansion valves

114a and 114b includes a three-way valve. Further, in some embodiments, the

expansion valves

114a, 114b are operably coupled (e.g., mechanically, electronically, and/or communicatively) to each other such that they are adjustable in series.

The valve assembly 114 facilitates the flow pattern (pattern) of the sample fluid. In the first flow mode, when adjusted to the "sample" position,

expansion valves

114a and 114b inhibit or prevent flow to expansion chamber 128 and allow sample fluid to flow in a closed loop between fluid source 10 and sample container 20. More specifically, fluid flows from the fluid source outlet 102 to the sample inlet 104 via the fluid conduit 106, and from the sample outlet 118 to the fluid source inlet 120 via the fluid conduit 122. Thus, the sample container 20 may be continuously "flushed" with fluid for a period of time (between about 15 minutes and 30 minutes) to remove potential contaminants from various components of the fluid sampling device 100, which may provide a more representative sample. In the second flow mode, when adjusted to the "expanded" position, the

expansion valves

114a and 114b inhibit or prevent flow to the fluid source 10 and allow sample fluid to flow in a closed loop between the sample container 20 and the expansion chamber 128. More specifically, the fluid flows from the outlet port 118 to an inlet end 132 of the expansion chamber 128 and from an outlet end 134 of the expansion chamber to the inlet port 104. The expansion chamber 128 is maintained at a lower pressure than the sample container 20 and therefore creates a pressure differential that, upon pressure equalization, draws a portion of the fluid contained in the sample container 20. In some embodiments, expansion chamber 128 is maintained below a vacuum pressure of sub-atmospheric level (e.g., such as between about-100 psig to about-150 psig). When the sample fluid is a compressed gas (e.g., liquefied petroleum or natural gas), exposure to the low pressure of the expansion chamber 128 causes a portion (e.g., about 20%) of the compressed liquid in the sample container 20 to expand into a gas, thereby reducing the packing density of the sample container 20. Accordingly, expansion chamber 128 may be suitably configured to achieve a predetermined maximum fill density (e.g., about 80%) of sample container 20.

Pressure relief valve 140 is coupled to outlet end 134 of expansion chamber 128, and conduit segment 148 leads from pressure relief valve 140 to fluid source inlet 120. The pressure relief valve 140 can be configured to automatically open and vent fluid from the expansion chamber 128 and back to the fluid source 10 when a predetermined activation pressure (e.g., at least about 135psig, such as about 150psig) is reached. Further, as discussed below, the pressure relief valve 140 may also be operated via an override device (e.g., an override handle) to facilitate purging the sample fluid from the expansion chamber 128 with an inert gas as needed. In some examples, the override device is configured to open the pressure relief valve 140 without changing the predetermined activation pressure.

Still referring to fig. 1, fluid sampling apparatus 100 further includes an inert gas inlet 150 and a gas routing valve 152. In some embodiments, inert gas inlet 150 includes a coupling (e.g., a quick connect coupling) adapted to connect with mating hardware of inert gas source 30. In some embodiments, the inert gas source 30 comprises a pressurized container containing an inert gas. As used herein, inert gas refers to gases that do not react with the sample fluid, such as compressed air, carbon dioxide, nitrogen, and oxygen. Other suitable configurations for providing the inert gas source 30 are also within the scope of the present disclosure. Inert gas inlet 150 is coupled to gas routing valve 152 via conduit segment 154. In this example, gas routing valve 152 comprises a three-way valve that couples inert gas source 30 to booster pump 156. In some embodiments, booster pump 156 provides a boost ratio of between about 1.25 to about 10. In some embodiments, the booster pump 156 may boost the pressure of the sample fluid to about 150 psig. Booster pump 156 is designed to facilitate the sampling process in a variety of applications, including: the fluid source 10 does not provide a sufficient pressure differential to drive the sample fluid through the sampling device 100 and/or the liquefied sample fluid must be maintained above its vapor pressure to avoid flashing. Thus, booster pump 156 facilitates operation of fluid sampling apparatus 100 in various environments that do not include a separate pressure device (such as a storage tank transported on a train, truck, or barge).

Booster pump 156 includes a suction port 158, a discharge port 160, an intake port 162, and an exhaust port 164. The suction port 158 and the discharge port 160 are coupled to a pump portion 161 of the booster pump 156; and an intake port 162 and an exhaust port 164 are coupled to a driving portion 165 of the booster pump 156 for driving the pump portion 161. In some examples, pump portion 161 may include a piston-type device or a plunger-type device designed to pressurize the pressure of the sample fluid when driven by drive portion 165. Thus, during sampling, the booster pump 156 is designed to receive relatively low pressure fluid from the sample source at the suction port 158 and to discharge the fluid at a higher pressure via the discharge port 160. In this example, the drive portion 165 is urged by pressurized gas from the inert gas source 30. Once the stored energy has been converted into mechanical work to operate the pump section 161, inert gas enters the pneumatic drive section 165 of the booster pump via the gas inlet 162 and is ejected from the pump 156 through the gas outlet 164. A check valve 166a is disposed immediately downstream of exhaust port 160 on conduit segment 167 to inhibit or prevent fluid from flowing back through booster pump 156. As shown, conduit segment 167 intersects fluid conduit 106 which directs sample fluid to expansion valve 114 a. When booster pump valve 110 (a three-way valve in this example) is adjusted to a "sample boost" position, fluid from fluid source 10 is directed via conduit segment to suction port 158 of booster pump 156 to be pressurized. Conversely, when booster pump valve 110 is adjusted to the "Sample Straight" position, Sample fluid is blocked at suction port 158 and directed to expansion valve 114a directly, bypassing booster pump 156, via conduit segment 112. As described above, the "sample-direct" position may be used when the fluid sampling device 100 is installed for use with a fluid source 10 that provides sufficient pressure to the sample fluid.

As described above, an inert gas may be used to drive the booster pump 156. Additionally, an inert gas may be used to purge the sampling device 100 of residual fluid from a previous sampling operation. When gas routing valve 152 is adjusted to the "run" position, inert gas is directed to gas inlet 162 of booster pump 156 via conduit segment 168, and sampling operations may proceed as described above. In some embodiments, gas routing valve 152 may also be adjusted to an "off" position (not shown) when booster pump 156 is not in use. However, when the gas routing valve 152 is adjusted to the "purge" position, the inert gas is blocked from the gas inlet 162 and alternatively may be directed to a conduit segment 169 equipped with a check valve 166b to inhibit or prevent backflow. If booster pump valve 110 is adjusted to the "sample flow" position, inert gas enters suction port 158 of booster pump 156 and purges pump section 161. If the booster pump valve 110 is adjusted to the "sample boost" position, at least a portion of the inert gas is pushed back through the booster pump valve 110 to purge the fluid source outlet 102.

The inert gas passing through booster pump 156 enters fluid conduit 106 leading to expansion valve 114 a. When the

expansion valves

114a and 114b are adjusted to the "sample" position, an inert gas is directed through sections of the

fluid conduits

106 and 122 to purge the sample inlet 104 and the sample outlet 118. The inert gas and any purged fluid then exit the sampling device 100 through the fluid source inlet 120. In some embodiments, sample container 20 is replaced with a conduit segment (not shown) to maintain fluid flow between sample inlet 104 and sample outlet 118 during the purge process. When the

expansion valves

114a and 114b are adjusted to the "expanded" position, the inert gas is directed from the outlet port 118 to the inlet end 132 of the expansion chamber 128 via conduit segment 136. An inert gas is forced through the expansion chamber 128 to purge the body 130. Further, during a purge operation, the pressure relief valve 140 is operated to an open position via an override device, allowing the inert gas and any sample fluid purged from the expansion chamber 128 to exit the sampling device 100 via the fluid source inlet 120. Once the fluid sampling device has sufficiently purged the residual sample fluid, the expansion chamber 128 can be brought back to vacuum pressure using a vacuum port 137 coupled to the inlet end 132 of the chamber 128.

Fig. 2 is a perspective view of a portable fluid sampler 200. In this example, portable fluid sampler 200 includes a housing 270 that supports an arrangement of components similar to or related to those described above in connection with sampling device 100 of fig. 1. Accordingly, the various components carried by the housing 270 and shown in fig. 2 may be described with reference to corresponding structures from the sampling device 100. As shown in fig. 3, the housing 270 is a portable structure that can be easily transported throughout a worksite by a user grasping the handle 271 and carrying the housing 270. Returning to fig. 2, in this example, the housing 270 comprises a clamshell structure characterized by a base 272 hingedly attached to a cover 274. The base 272 and the cover 274 together define an interior cavity 276. In some examples, the cover 274 may be locked to the base 272 to close the housing 270 (e.g., during transport by a user, as shown in fig. 3). The faceplate 278 is mounted to the base 272 of the housing 270. Some of the components described below that are carried by the housing 270 are mounted on the panel 278, while other components may be located in a recess in the base 272 of the housing below the panel 278.

As shown in fig. 2, the face plate 278 supports the fluid source outlet 202, the fluid source inlet 220, the sample inlet 204, and the sample outlet 208. Fluid source outlet 202 and fluid source inlet 220 may be coupled to a suitable source of sample fluid, which may or may not provide sufficient pressure to circulate fluid through fluid sampling device 200. As described above, fluid received at the fluid source outlet 202 may be circulated to a sample container (e.g., sample container 20) coupled to the sample inlet 204 and the sample outlet 208 via one or more fluid conduit segments located below the panel 278. The face plate 278 further supports an inert gas inlet 250, which inert gas inlet 250 may be coupled to a pressurized source of inert gas (e.g., inert gas source 30) for purging the fluid sampling apparatus 200 and/or for driving a booster pump (e.g., booster pump 156) configured to increase the pressure of the sample fluid from the fluid source (e.g., fluid source 10). The face plate 278 further supports a vacuum port 237 coupled to an inlet end of an expansion chamber (e.g., expansion chamber 128) located below the face plate 278. As described above, once the fluid sampling device has sufficiently purged the residual sample fluid, the expansion chamber can be restored to vacuum pressure using the vacuum port 237. In some embodiments, an external 1,000cc cylinder, already primed to a vacuum pressure of about-200 psig, may be coupled to vacuum port 237 to restore the vacuum pressure of the expansion chamber.

The face plate 278 further includes four valve actuation handles 280, 282, 284, and 286. The first valve actuation handle 280 is mounted to operate an expansion valve assembly (e.g., valve assembly 114) configured to control the flow of fluid between the outer sample source, the outer sample container, and the expansion chamber. Valve actuation handle 282 is mounted to operate a booster pump valve (e.g., booster pump valve 110) configured to regulate a flowing sample fluid to a suction port of a booster pump located below panel 278. A valve actuation handle 284 is mounted to operate a gas routing valve (e.g., gas routing valve 152) configured to control the flow of inert gas between the intake and the intake ports of the booster pump located below the panel 278. The valve actuation handle 286 is mounted to operate a pressure relief valve (e.g., pressure relief valve 140) that is configured to automatically purge the expansion chamber located below the panel 278 when a predetermined activation pressure is reached. Thus, in this example, the valve actuation handle 286 serves as a manual override to open and close the pressure relief valve, for example, to facilitate purging the sample fluid from the expansion chamber with an inert gas as needed, as described below with respect to the process 600 of fig. 6. The pressure indicator 288 is mounted to provide pressure readings of the fluid circulating through the sampling device 200. Thus, for example, during a sampling process, a user may determine whether to engage an internal booster pump to inhibit or prevent flashing of the sample fluid.

Fig. 4 is a flow chart illustrating a process 400 of operating a fluid sampler. FIG. 5 is a flow chart illustrating a process 500 for collecting a fluid sample using a fluid sampling device. FIG. 6 is a flow chart illustrating a process 600 for purging a fluid sampling device with an inert gas.

Processes

400, 500, and 600 may be implemented, for example, in conjunction with one or more components of fluid sampling device 100 shown in fig. 1 and/or portable fluid sampling device 200 shown in fig. 2. Moreover, the operations of the processes need not be in any particular order to achieve desirable results. In addition, other operations may be provided from the described processes, or operations may be eliminated, without departing from the scope of the disclosure.

According to the process 400 of FIG. 4, a fluid sample is collected (402) via closed loop circulation of the fluid sample through a fluid sampling device, a fluid source, and a sample container. As described above, the fluid sampling device may include one or more fluid conduits, valves, and chambers to facilitate circulation of the sample from the fluid source to the sample container. The fluid source may include a treatment system for treating a fluid (e.g., a hydrocarbon fluid), a tank for storing the fluid, and/or any other suitable device or apparatus for containing or transporting the fluid. The sample fluid may comprise liquefied petroleum gas, liquefied natural gas, or any other recyclable fluid (e.g., compressed gas). The sample container and expansion chamber may comprise any size or type of pressure vessel suitable for containing a sample fluid. In some embodiments, the sample container may comprise a metallic, pressure-rated cylinder equipped with an inlet isolation valve and an outlet isolation valve. Once the sample is collected (402), the sample container is removed (404) from the fluid sampling device. After the sample container is removed (404), the fluid sampling device is purged (406) through the fluid sampling device via circulation of an inert gas. The inert gas may include any gas phase fluid that does not react with the sample fluid (e.g., compressed air, carbon dioxide, nitrogen, and oxygen). The circulated inert gas and purged sample fluid are deposited (408) directly into the fluid source. For example, as described above, the inert gas and the sample fluid may be circulated through various components of the fluid sampling device for purging and then directed through a fluid source inlet coupled to a fluid source.

According to the process 500 of fig. 5, a fluid source inlet and a fluid source outlet of a fluid sampling device according to one or more embodiments of the present disclosure are coupled (502) to a suitable fluid source. The sample inlet and outlet of the fluid sampling device are coupled (504) to a suitable sample container. Optionally, an internal booster pump may be operated to maintain the sample fluid at a suitable pressure. To engage the booster pump, coupling (506) an inert gas inlet of the fluid sampling device to an inert gas source; adjusting (508) the gas routing valve to a "run" position; and adjusting (510) the booster pump valve to a "sample boost" position. Alternatively, to bypass the booster pump, the gas line valve may be adjusted to an "off" position, the booster pump valve may be adjusted to a "sample flow" position, and/or the inert gas source may be decoupled from the inert gas inlet. The expansion valve assembly is adjusted (512) to a "sample" position regardless of the state of the booster pump. A flow of sample fluid through the fluid source outlet is initiated (514) and the flow of sample fluid is allowed to circulate (516) through the fluid sampling device to flush the sample container. As described above, in some examples, a fluid sampling device is configured to facilitate closed-loop circulation of a sample fluid between a sample container and a fluid source. Once the sample container has been flushed, the expansion valve assembly is adjusted (518) to an "expanded" position and the pressure between the sample container and the internal expansion chamber is allowed to stabilize (520). As described above, in some examples, the expansion chamber is maintained at a relatively low pressure (e.g., vacuum pressure) as compared to the sample container, such that the pressure differential causes a portion of the fluid to vacate the sample container to facilitate the expansion chamber. In some embodiments, where the sample fluid is a compressed gas, at least a portion of the fluid in the sample container may undergo a liquid-gas phase change due to pressure stabilization. After the fluid sample has been expanded, fluid flow through the fluid source outlet is stopped (522), and the sample container is disconnected from the fluid sampling device (524).

According to the process 600 of fig. 6, a conduit segment (602) is inserted through a sample inlet and outlet of a fluid sampling device, replacing a disconnected sample container. The expansion valve assembly is adjusted (604) to a "sample" position, providing a continuous flow path between the fluid source outlet and inlet, through the inserted conduit segment. The gas routing valve is adjusted (606) to a "purge" position. The booster pump valve is adjusted (608) to a "sample flow through" position. A flow of inert gas is initiated (610) through the inert gas inlet and the inert gas is allowed to circulate (612) through the fluid sampling device to purge residual fluid from a sampling process (e.g., sampling process 500 of fig. 5) in components of the sampling device. The booster pump valve is adjusted (614) between "sample flow" and "sample boost" positions. As described above, when the booster pump valve is in the "sample boost" position, the inert gas is pushed back through the booster pump valve and the fluid source outlet. Thus, in some examples, adjusting the booster pump valve back and forth may result in a discrete "puff" or "jet" of inert gas to purge sample fluid of those components that may be bypassed while the booster pump valve remains in the "sample flow" position. Returning to fig. 6, the expansion valve assembly is adjusted 616 to an "expanded" position, exposing the inlet end of the expansion chamber to the inert gas flow. The pressure relief valve is opened (618) exposing the outlet end of the expansion chamber to the fluid source inlet. The expansion valve assembly is adjusted (620) between an "expansion" position and a "sample" position to cause discrete "jets" or "jets" of inert gas to purge the expansion chamber. The inert gas purged from the expansion chamber and the residual sample fluid flow directly to the fluid source via the fluid source inlet. Once the fluid sampling device has sufficiently purged the residual sample fluid, the expansion chamber is restored (622) to vacuum pressure using a vacuum port at the chamber inlet end.

A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention.

Claims

1. A fluid sampling device, comprising:

a first conduit configured to couple an outlet of a fluid source to a sample inlet;

a second conduit configured to couple a sample outlet to an inlet of the fluid source;

an expansion chamber comprising an inlet and an outlet, the outlet coupled to the first conduit through a valve assembly, the inlet coupled to the second conduit through the valve assembly;

a pressure relief valve configured to couple the outlet of the expansion chamber to the inlet of the fluid source,

a sample container coupled to the sample inlet and the sample outlet;

wherein the first conduit is further configured to be coupled to a source of inert gas such that:

when the valve assembly is in the first position, inert gas from the inert gas source that is not reactive with fluid of the fluid source pushes fluid within the first and second conduits toward the inlet of the fluid source, thereby purging the first and second conduits, and

when the valve assembly is in the second position and the pressure relief valve is open, inert gas from the inert gas source pushes fluid within the expansion chamber toward the inlet of the fluid source, thereby purging the expansion chamber;

wherein when the valve assembly is in a first position, fluid from the fluid source flows in a closed loop between the sample container and the fluid source, thereby flushing the sample container, and

wherein when the valve assembly is in the second position, the fluid flows in a closed loop between the sample container and the expansion chamber, thereby expanding a portion of the fluid in the sample container.

2. The fluid sampling device of claim 1, wherein the fluid comprises a liquefied gas.

3. The fluid sampling device of claim 1, wherein the inert gas comprises at least one of: carbon dioxide, molecular oxygen and molecular nitrogen.

4. The fluid sampling device of claim 1, comprising a portable housing supporting the first and second conduits, the expansion chamber, and the pressure relief valve.

5. The fluid sampling device of claim 1, wherein the sample inlet and the sample outlet comprise quick connect fittings.

6. The fluid sampling device of claim 1, wherein the valve assembly comprises a series valve comprising a pair of three-way valves, a first of the three-way valves coupling the inlet of the expansion chamber to the second conduit and a second of the three-way valves coupling the outlet of the expansion chamber to the first conduit.

7. The fluid sampling device of claim 1, comprising a booster pump configured to be coupled to the first conduit, wherein operation of the booster pump induces fluid from the outlet of the fluid source to flow through the first conduit to the sample inlet.

8. The fluid sampling device of claim 7, wherein the booster pump comprises a gas driver, and wherein a gas inlet of the gas driver is configured to be coupled to the inert gas source.

9. The fluid sampling device of claim 8, comprising an inert gas routing valve configured to regulate coupling of the inert gas source between the first conduit and the gas inlet of the gas driver of the booster pump.

10. The fluid sampling device of claim 7, comprising a booster pump valve configured to regulate coupling of the first conduit with a high pressure outlet of the booster pump.

11. The fluid sampling device of claim 7, comprising a portable housing supporting the first and second conduits, the expansion chamber, and the booster pump.

12. The fluid sampling device of claim 11, wherein the booster pump comprises a gas driver, and wherein a gas inlet of the gas driver is configured to be coupled to an inert gas source.

13. The fluid sampling device of claim 12, comprising an inert gas routing valve configured to regulate coupling of the inert gas source between the first conduit and the gas inlet of the gas driver of the booster pump.

14. The fluid sampling device of claim 11, comprising a booster pump valve configured to regulate coupling of the first conduit with a high pressure outlet of the booster pump.

15. The fluid sampling device of claim 11, wherein the valve assembly comprises a series valve comprising a pair of three-way valves, a first of the three-way valves coupling the inlet of the expansion chamber to the second conduit and a second of the three-way valves coupling the outlet of the expansion chamber to the first conduit.

16. A method of purging the fluid sampling device of claim 1, the method comprising:

coupling a fluid conduit of the fluid sampling device to an inert gas source;

circulating the inert gas through the fluid conduit;

circulating the inert gas through an expansion chamber of the fluid sampling device; and

depositing at least a portion of the inert gas and at least a portion of any sample fluid purged from the fluid conduit and the expansion chamber directly from the fluid sampling device to the sample fluid source coupled to the fluid sampling device.

17. The method of claim 16, wherein the inert gas is non-reactive with the fluid of the fluid source and comprises at least one of: carbon dioxide, molecular oxygen and molecular nitrogen.

18. The method of claim 16, comprising circulating the inert gas through a valve assembly comprising a series valve, the series valve comprising a pair of three-way valves, a first of the three-way valves coupling an inlet of the expansion chamber to the fluid conduit and a second of the three-way valves coupling an outlet of the expansion chamber to the fluid conduit.

19. The method of claim 18, comprising adjusting the valve assembly between a first position and a second position to circulate a discrete jet of inert gas through the expansion chamber.

20. The method of claim 18, comprising engaging an override device of a pressure relief valve coupled to the outlet of the expansion chamber to fluidly couple the expansion chamber with the sample fluid source.